The present invention relates to fiber optic cables, and, more particularly, to fiber optic cables that include at least one optical transmission component and at least one strength component.
Fiber optic cables include at least one optical fiber that can transmit data, computer, and/or telecommunication information. Conventional cable designs, however, can have unacceptable optical performance characteristics, and/or can require undesirable structural features that make optical fiber access difficult. In addition, conventional cables can be difficult to route through cable passageways, and/or can make the cable expensive to produce.
Cable designs that define a backdrop for the present inventions can be, for example, difficult to route through cable passageways and/or can be expensive to produce. U.S. Pat. No. 5,155,304 discloses an aerial service wire that includes a PVC jacket having a generally block-shaped cross section. Enclosed by the jacket are two groups of strength components, each of which includes a plurality of filaments that are impregnated with a plastic material. Moreover, conventional aerial fiber optic cables can be too large for some applications. For example, EP-A1-0629889 discloses an aerial cable requiring an optical cable central part with two metallic strain relief elements that are placed diametrically opposite to each other and adjacent the optical cable part. The strain relief elements are connected to the cable part by means of a jacket that includes web-like extensions between the optical cable part and the strain relief elements. In addition, optical cables of the single fiber type may not provide adequate data transmission capacity.
In an aspect of the present invention a flexible fiber optic cable having good tensile strength has at least one optical transmission component and at least two strength components, with at least one tensile strength member disposed between the optical transmission component and at least one strength component. The tensile strength member is preferably multi-functional in that it provides at least tensile strength and waterblocking enhancements. At least one of the strength components can have a nominal radius that is less than the nominal radius of the optical transmission component. The cable has a cable jacket surrounding the optical transmission component, the strength members, and the strength components. The cable has a jacket surrounding the optical transmission component and the strength components.
In another aspect of the invention a fiber optic cable comprises at least two strength components, an optical transmission component, and at least one tensile strength member disposed generally adjacent at least one of the strength components, a single strength member to a single strength component tensile strength rating ratio being about 0.1 to about 0.3. In another aspect, an overall multiple strength members to multiple strength components tensile strength rating ratio being about 0.25 to about 0.5.